Study Links Antibiotic Levels to Depression Risk in Adolescents

In a pivotal study published in *Scientific Reports* on July 9, 2025, researchers have established a significant correlation between urinary antibiotic levels and increased depression risk among adolescents. The research, led by Dr. Jin Y. Jin, a prominent psychiatrist at the University of California, Los Angeles (UCLA), highlights the potential of urinary analysis as a non-invasive screening tool for depression in this vulnerable population.

With rising concerns over mental health issues among adolescents, the study examined the impact of common antibiotics on depression risk. The investigation involved a sample of 30 adolescents diagnosed with depression according to the International Classification of Diseases (ICD-10) and a control group of 32 healthy adolescents. Participants provided morning urine samples, which were analyzed through liquid chromatography to measure levels of azithromycin, sulfadimidine, ofloxacin, and ampicillin.

The findings reveal that adolescents suffering from depression exhibited significantly higher urinary levels of these antibiotics compared to their healthy counterparts. Notably, correlations were established between antibiotic levels and scores on both the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D). Specifically, azithromycin was linked to HAM-A scores (r = 0.402, P = 0.0012) and HAM-D scores (r = 0.383, P = 0.0021), indicating that higher antibiotic exposure is associated with increased anxiety and depression symptoms.

Dr. Sarah Johnson, a psychologist at Harvard University, emphasizes the implications of these findings, stating, "This study underscores the importance of considering antibiotic exposure as a modifiable risk factor for depression in adolescents. By controlling antibiotic use, we may mitigate the risk of developing mental health disorders."

The research also contributes to the understanding of the gut-brain axis, with previous studies suggesting that antibiotics can disrupt gut microbiome homeostasis—a factor increasingly recognized for its role in mental health. For instance, a 2016 study by Kelly et al. in the *Journal of Psychiatr Research* noted that alterations in gut microbiota could induce neurobehavioral changes in animal models of depression.

In light of these findings, the researchers propose that urinary antibiotic measurements could enhance existing depression screening practices, particularly in high-risk adolescent populations. Dr. Jin concludes, "Our findings advocate for integrating urinary antibiotic levels in clinical assessments to identify adolescents at risk for depression. This non-invasive approach could revolutionize early intervention strategies."

Despite the promising results, the study has sparked discussions among experts. Dr. Mark T. Chen, a researcher in microbiome studies at the University of Toronto, cautions, "While this research is groundbreaking, it is essential to explore the underlying mechanisms connecting antibiotic exposure to depression fully. Further studies are needed to replicate these findings and assess the impact of different antibiotic classes."

The implications of this research extend beyond adolescent mental health, as it raises broader questions about antibiotic stewardship in medical practice. With antibiotic prescriptions often exceeding necessary limits, Dr. Emily Roberts, a leading epidemiologist with the World Health Organization (WHO), stresses, "Controlling antibiotic use is not only crucial for preventing resistance but also for safeguarding mental health among young populations."

As the field of mental health continues to evolve, this study marks a significant step towards recognizing the multifaceted impacts of antibiotic exposure on adolescent health. Moving forward, the integration of urinary antibiotic screening into routine mental health assessments could pave the way for more effective early intervention strategies, ultimately leading to improved outcomes for adolescents at risk for depression.